From sivanov@clari.net Fri Oct 18 12:50:37 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!clari!sivanov From: sivanov@clari.net (Sven Ivanov) Newsgroups: comp.sys.m68k Subject: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Oct18.125037.3426@clari.net> Date: Fri, 18 Oct 1996 12:50:37 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: WinVN 0.99.5 Lines: 10 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Sven Ivanov Tape trading list upon request. SASE required for international mail. From sito@unam.mx Fri Oct 18 20:47:37 1996 Path: ashpoly!cascade!mxgate!coyoacan!unam!sito From: sito@unam.mx (Sun-mi Ito) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Oct18.204737.9344@unam.mx> Date: Fri, 18 Oct 1996 20:47:37 GMT References: <1996Oct18.125037.3426@clari.net> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 11 In article <1996Oct18.125037.3426@clari.net>, sivanov@clari.net (Sven Ivanov) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Sun-mi Ito | sito@unam.mx PGP Key fingerprint: 3FFC 52D4 17A9 80FA "Keep the channels open." From rhughes@netcom.com Sun Oct 20 07:02:37 1996 Path: ashpoly!cascade!bigsur!netcom!rhughes From: rhughes@netcom.com (Raj Hughes) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Oct20.070237.3826@netcom.com> Date: Sun, 20 Oct 1996 07:02:37 GMT References: <1996Oct18.125037.3426@clari.net> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Oct18.125037.3426@clari.net>, sivanov@clari.net (Sven Ivanov) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Raj Hughes -- NETCOM On-Line Communication Services "We don't sign stars. We build them." From jhernandez@u-tokyo.ac.jp Sun Oct 20 12:57:37 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!jhernandez From: jhernandez@u-tokyo.ac.jp (Ji-woo Hernández) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Oct20.125737.6447@u-tokyo.ac.jp> Date: Sun, 20 Oct 1996 12:57:37 GMT References: <1996Oct18.125037.3426@clari.net> <1996Oct20.070237.3826@netcom.com> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996Oct20.070237.3826@netcom.com>, rhughes@netcom.com (Raj Hughes) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Top-posters will be placed in my ~/.killfile without notice. -- Ji-woo Hernández Hayes Optima 288 @ 19,200 bps "There are 14 nodes and only 10 countries. Count again." From dramirez@earthlink.net Mon Oct 21 08:12:37 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!earthlink!dramirez From: dramirez@earthlink.net (Dmitri Ramírez) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Oct21.081237.4382@earthlink.net> Date: Mon, 21 Oct 1996 08:12:37 GMT References: <1996Oct18.125037.3426@clari.net> <1996Oct20.070237.3826@netcom.com> <1996Oct20.125737.6447@u-tokyo.ac.jp> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Oct20.125737.6447@u-tokyo.ac.jp>, jhernandez@u-tokyo.ac.jp (Ji-woo Hernández) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- === Dmitri Ramírez === Dept of Electrical Engineering, EarthLink Network "There are 14 nodes and only 10 countries. Count again."